window.onload=function(){
    //获取cookie
   let cookieStr= document.cookie;
   let cookirArr=cookieStr.split(";");
   let bool=false;
   let username;;
   for(let i=0;i<cookirArr.length;i++){
        //去除空格
     let str=cookirArr[i].trim();

      let key="username=";
      if(str.startsWith(key)){
        bool=true;
        username=str.substring(key.length,str.length);
        break;
      }
   }

   //判断bool标记值
   if(bool){
    console.log(username);
   }else{
        location.href='登录注册.html'
   }
}